Diabetes is the leading cause of nontraumatic amputation in the U.S. Diabetic neuropathy is largely responsible for the non-healing lower limb ulcers that lead to amputation. Thermal biofeedback training may be a noninvasive, inexpensive way to help patients speed ulcer healing by increasing rate of blood flow and oxygen perfusion into peripheral tissue. The current study will test the hypothesis that foot temperature is positively associated with ulcer healing and that type and severity of neuropathy are related to ability to raise foot temp.